Methods and biocides are known for combating the biodegradation of waters by fouling agents. Romanian Pat. No. 57,257, representative of this prior art, discloses a solution containing biocidal substance only, within a suitable solvent, and having a viscosity adapted to promote deep capillary pentration into the concrete.
The disadvantages of the prior art as exemplified by that patent are:
(a) the necessity to apply four layers of paint;
(b) no provision for strengthening the surface structure of the cured concrete;
(c) does not change the biocide used in accordance with the particular fouling agents present;
(d) makes no provision for a supplementary mechanical-fixation treatment with biocide at the same time--apart from the basic treatment with biocide itself--such provision being necessary where the friction phenomenon is significant;
(e) makes no provision for the separate application of both biocides in stages.